Abstract:

A Gram-negative, rod shaped, motile bacterium, was isolated from a marine solar saltern sample collected from Kakinada, India. Strain AK2 sup(T) was determined to be positive for nitrate reduction, catalase, Ala-Phe-Pro-arylamidase, beta-galactosidase, beta-N-acetylglucosaminidase, beta-glucosidase, beta-xylosidase, alpha-glucosidase, alpha-galactosidase and phosphatase activities, hydrolysis of aesculin, Tween 20/40/60/80 and urea. It was determined to be negative for oxidase, lysine decarboxylase and ornithine decarboxylase activities and could not hydrolyze agar, casein, gelatin and starch. The predominant fatty acids were identified as iso-C sub(15:0) (28.2 percent), anteiso-C sub(15:0) (23.2 percent), iso-C sub(13:0) (19.9 percent) and iso-C sub(15:0) 3-OH (13.9 percent). Strain AK2 sup(T) was found to contain menaquinone with seven isoprene units (MK-7) as the sole respiratory quinone and phosphatidylethanolamine, one unidentified phospholipid and three unidentified lipids as polar lipids. The 16S rRNA gene sequence analysis indicated the strain AK2 sup(T) as a member of the genus Marinilabilia and is closely related to Marinilabilia salmonicolor with pair-wise sequence similarity of 98.2 percent. Phylogenetic analysis of 16S rRNA gene revealed that the strain AK2 sup(T) clustered with M. salmonicolor. However, DNA-DNA hybridization with M. salmonicolor JCM21150 sup(T) showed a relatedness of 48 plus or minus 0.5 percent with respect to strain AK2 sup(T). The DNA G+C content of the strain was determined to be 40.2 molpercent. Based on the phenotypic characteristics and phylogenetic inference, it is proposed that the strain AK2 sup(T) represents a novel species of the genus Marinilabilia, for which the name Marinilabilia nitratireducens sp. nov. is proposed. The type strain of M. nitratireducens sp. nov. is AK2 sup(T) (= MTCC 11402 sup(T) = JCM 17679 sup(T)).

Copyright:An edited version of this paper was published by Springer. This paper is for R & D purpose and Copyright [2012] Springer.